A known radiation computed tomography technique comprises: irradiation of a test object with a flux of ionizing radiation, registration of the radiation passed along a preset number of paths through a test object which, as well as the “pack” of detectors, move relatively and angularly, transformation of the registered signals, and computerized reconstruction of the tomographic image according to a certain algorithm. The said radiation from a point source propagates in the form of fan-shaped beam and after its transit through the test object is registered by detectors located on a circular arc having the centre in the radiation source point (see Patent for Invention RU No. 2180745, IC: G01N23/04).
Though, the known technique allows to determine the structure of an object, the inner one including, the resolution characteristics depend on the size of detectors and the scanning pitch, and cannot be detailed closer than several millimeters.
In technical essence, nearest to the applied method stands the procedure of tomographic testing, comprising: scanning of a test object by a fan-shaped beam from a point source of radiation by shuttling and discretely turning the object under test, registration of the radiation intensity passed through the test object by means of a detector matrix with subsequent computer processing the obtained information, and, on its basis, reconstruction of the object internal structure. The view locality and its dimensions within a test object are preliminarily specified and then entered into a computer, after which the test object is being rapidly scanned until the moment when a border of the view locality crosses the outer ray of the fan-shaped beam that falls on the first detector of the matrix, whereupon slow scanning is performed with the scanning pitch reduced by K=D/DJI, where D is the dimension of the test object, DJI is the dimension of the view locality. The interval of reading samples from the detectors is decreased by K, while only a part of matrix detectors are activated for the registration depending on the size of the view locality (see Patent for Invention RU No. 2097748, IC: G01N23/04).
The above approach enables improvement of resolution up to a certain limit due to the reduced scanning pitch, however, detectors' geometric dimensions do not provide the required resolving ability.
A known embodiment includes a confocal scanning tomographic microscope, comprising: a primary pinpoint source of light, a mobility device for a three-dimensional test object, a condenser lens adapted to focus radiation from the primary pinpoint light source in a point inside the 3D test object positioned on the mobility device, a microobjective forming an image of the secondary light source derived from the focused radiation of the primary pinpoint source of light, a pinhole diaphragm located in the image plane of the secondary light source, and a radiation detector. The radiation detector is placed at a distance behind the pinhole diaphragm and is implemented in the form of an optical receiver matrix, and between the pinhole diaphragm and the optical receiver matrix a diffraction optical element is introduced (see Patent for Invention RU No. 2140661, IC: G02B21/00).
Nevertheless, the known embodiment configured to scan three-dimensional objects is characterized by a low resolution capability.
Most closely in technical substance, the presented device is approached by the confocal scanning microscope which comprises: a radiation source unit, an opaque screen with a slit installed together with the confocally fixed first and second focusing devices along the beam path in the microscope optical route, as well as the microscope object stage mounted on a means of mobility in the focal plane common for all these devices, and an optical receiver disposed in the image plane. To unify and simplify the microscope construction to enable imaging in a wide spectral range while maintaining an admissible energy deposition on a test sample the opaque screen with a slit is configured immobile the slit being of a rectangular shape, the object stage is rigged with a device providing linear movement of a test specimen during image formation, and the optical receiver being aligned with the slit image is configured as a line of photosensors linked to a line-by-line imaging device (see Patent for Invention RU No. 2018891, IC G02B21/00).
Just the same, resolution characteristics of the known embodiment is restricted by the width of the slit which cannot be smaller than 10 microns for the radiation applied because of diffraction.